1. Field of the Invention
This invention relates generally to plastic beverage containers and more particularly to containers for carbonated beverages and other pressurized products which are blow-molded so as to have a semi-hemispherical bottom, and most particularly to a base-cup attachment thereto for supporting the bottle in an upright position.
The specific improvement provided by the present invention is the existence of means within the base-cup for preventing the over-insertion of the bottle into the base cup thereby effectively assuring vertical alignment of the bottle.
2. Description of Prior Art
In recent years, blow-molded plastic bottles for containing carbonated beverages such as beer, colas, and the like have been developed which typically employ very thin wall sections and include a round or semi-hemispherical bottom for containing the internal pressure of the carbonated beverage. The presence of the semi-hemispherical bottom end of the bottle does not permit the bottle to stand upright on a shelf or table top without the addition of some auxillary base. The base has typically taken the form of a shallow cup having an inwardly projecting annular ring at the lip of the cup which engages an indentation present at a lower portion of the otherwise generally cylindrical body of the bottle. The term "semi-hemispherical" is intended to include any hemispherical-like shape including that of an elipsoid, a paraboloid, or other similar variant.
The line of inter-engagement between the annular ring at the lip of the supporting base-cup with the indentation in the side wall of the bottle body constitutes a reference line about which the body of the bottle expands axially when the bottle is sealed with a carbonated beverage inside. That is, the presence of the carbonation causes an elevation in the pressure within the bottle thereby causing the bottle to axially elongate. Thus, the base-cup must provide sufficient room for this axial elongation by maintaining a space of sufficient dimension between the bottom of the bottle in its unpressurized condition and the bottom of the base-cup. A failure to provide such a space causes the bottle to expand to such an extend as to press downward on the bottom of the base-cup and distort the base-cup into an unstable configuration.
If sufficient space is provided for this axially elongation, a further difficulty is presented, in that, the unpressurized or empty bottle can be inserted too far into the base-cup beyond the point of inter-engagement between the annular ring at the lip of the base-cup and the indentation in the bottle body. In the absence of this inter-engagement between the indentation and the annular ring of the cup, the bottle can become axially misaligned with respect to the cup so as to no longer stand in a perfectly upright position.
It is, therefore, an object of the present invention to provide a base-cup for use with a blow-molded plastic bottle of contemporary design which permits the axial expansion of the bottle under pressure, but prevents the over-insertion of the bottle into the base-cup thereby ensuring vertical alignment of the bottle and base-cup.